Fix saved searces, news updates, ip bans being dumped to BigQuery.

Prevent saved searches, news updates, and ip bans from being publicly
dumped to BigQuery. They didn't override the `visible` method to
restrict their visibility for anonymous users.

app/controllers/news_updates_controller.rb

@@ -1,9 +1,9 @@
 class NewsUpdatesController < ApplicationController
-  respond_to :html
+  respond_to :html, :json, :xml
 
   def index
     authorize NewsUpdate
-    @news_updates = NewsUpdate.order("id desc").paginate(params[:page], :limit => params[:limit])
+    @news_updates = NewsUpdate.visible(CurrentUser.user).paginated_search(params, count_pages: true)
     respond_with(@news_updates)
   end